The present invention comprises a new and distinct cultivar of birch tree, botanically known as Betula platyphylla, and hereinafter referred to by the cultivar name ‘VerDale’. ‘VerDale’ is a product of a planned tree selection program which had the objective of creating a new cultivar of birch tree having high bronze birch borer resistance, good birch leafminer resistance and various aesthetic qualities as listed in the Detailed Description of the Plant.
The new cultivar is a selection of Betula platyphylla, and was discovered by applicant among seedlings grown from parental trees growing on the NDSU campus and was transplanted on Sep. 22, 1975 into the NDSU Research Arboretum, Absaraka, N. Dak. The selection was noticed by virtue of its long term bronze birch borer resistance; white bark; quality dark green foliage and excellent golden-yellow autumn foliage coloration; upright, oblong-elliptical form becoming broadly pyramidal with maturity.
The first act of asexual reproduction of ‘VerDale’ was accomplished when plants were produced in tissue culture using standard micropropagation techniques by applicant from the initial selection on Nov. 13, 2000 in a controlled environment in Fargo, N. Dak. (NDSU). Horticultural examination of selected units initiated on Nov. 13, 2000 has demonstrated that the combination of characteristics as herein disclosed for ‘VerDale’ are firmly fixed and are retained through successive generations of asexual reproduction.
‘VerDale’ has not been observed under all possible environmental conditions. The phenotype may vary with variations in environment such as temperature, light intensity, and day length. The following observations, measurements and comparisons describe the plants grown in the NDSU Research Arboretum or under greenhouse conditions, which approximate those generally used in commercial practices.